Two cards are drawn at random from a pack of 52 cards. What is the probability that either both are black or both are queen?
A.4/26 B.55/221 C.56/221 D.55/220

• Probability of taking 2 from 52 cards = 52C2 = 52 * 51/2*1 = 1326
  
  There r 26 black cards
  There r 4 queens
  
  prob that both r black cards P(A)= 26C2/1326 = 26 * 25/2 * 1 = 325/1326
  prob that both r queens P(B)= 4C2/1326 = 4 * 3/2 * 1 = 6/1326
  P(A n B) = 2C2/1326 = 1/1326
  
  P(A U B) = P(A) + P(B) - P(A n B) = 325/1326 + 6/1326 - 1/1326
  => 55/221
  
  Ans : 55/221
  
  
  
  
  
• 10 years agoHelpfull: Yes(71) No(3)
• 55/221;ans
  exp;;26*25/52*51+4*3/52*51-2*1/52*51;=55/221
  
• 10 years agoHelpfull: Yes(4) No(1)
• how 52*51/2*1 become?
• 10 years agoHelpfull: Yes(2) No(6)
• 55/221 is correct ans:
• 10 years agoHelpfull: Yes(1) No(1)
• Probability of taking 2 from 52 cards = 52C2 = 52 * 51/2*1 = 1326
  
  There r 26 black cards 
  There r 4 queens
  
  prob that both r black cards P(A)= 26C2/1326 = 26 * 25/2 * 1 = 325/1326
  prob that both r queens P(B)= 4C2/1326 = 4 * 3/2 * 1 = 6/1326
  P(A n B) = 2C2/1326 = 1/1326
  
  P(A U B) = P(A) + P(B) - P(A n B) = 325/1326 + 6/1326 - 1/1326
  => 55/221
  
  Ans : 55/221
• 4 years agoHelpfull: Yes(0) No(0)